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pjvr99

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Posts posted by pjvr99

  1. FTR I was taught the following, no matter which engine is being started:

    at 60% the call out is "60% - release" to release starter button

    then either "Series" or "start light out" whichever order to confirm that speed switch has 

    disconnected ignition relay and put the fuel pumps to series, and that the starter valve has

    closed. Starter light still on at LSGI would require some really quick troubleshooting and engine

    shutdown if it is determined start valve is stuck open ...

  2. Never tow with scissors connected (beaten into us as apprentices). There is no requirement in towing job guide. However, there are several cautions and warnings to deplete system pressures, and ensure ground checkout valve is in normal (up) position before towing ....

  3. Quite normal. The starter is released at a nominal 60% rpm and the speed switch releases the parra valve at a nominal 65% rpm. Factors affecting these lights are:

    actual engine acceleration rate,

    actual rpm starter is released at,

    closing rate of starter valve,

    sensitivity of starter sensing switch,

    condition of starter sensing lines,

    actual rpm speed switch releases parra valve,

    response time of parra valve,

    efficiency of fuel pumps and,

    response/efficiency of bypass valve in resetting.

     

    Only requirement for sec fuel light is to come on before 65%

    and be off once engine has stabilized at LSGI, and not come on

    again at any speed or power setting.

  4. First one sounds like a bad fuel cluster, also pull the combustion liner and check for coking.

     

    Second could be a number of things: fuel cluster, speed switch, oil pressure sequencing switch, broken wire, dry solder joint on a cannon plug, bad 110% solenoid ..... be fun to debug it on test stand.

  5. On my test cell engine has to be complete, meaning transfer bar installed and set up. However, because throttle and condition is electric servos we only rig from coordinator to engine. Final rig when installing on the wing normally requires some adjustment of the gimbal cables. Always make sure throttle rig is good on 0°, 34° & 90° (rev, fi  & to) before attempting condition/feather rig

  6.  

     

     

    Ok, we hooked up the starter air duct and starter sensing line to the scav filter in and outlet transducers. We use an AM32A-60A power unit to start the engine. In the first vid, we just motor the engine over to maximum rpm. In the second, it is a full start to lowspeed ground idle .....

    I dont really see how a sensing line pressure equal to the delivery pressure is possible. I suspect the 36.5 to 42 psi may be from using engine pressure of 70 to 80psi, with the starter valve modulating the pressure to 36 to 42psi ....

    In other words, the SP213 card may be wrong. Hope this helps ....

  7. I understand what you're saying, having read through the card. It just seems that youre trying to do individual component testing on parts that should be checked on a bench. 

     

    The only places i know of that uses "hg is the cabin pressure differential, engine lighthouse area and the apu bleed air regulator. All other pressures are psi. 

     

    For conversion 14.69psi = 29.91"hg

  8. With cc pack on bleed air pressure should be around 35ps (32psi minimum), both packs should max out egt and pressure as low as 10psi, and unloaded should be above 38psi. Check air pressure regulator for 18.5 to 19.5psi

     

    Assuming load control valve and thermostat have been replaced, you are probably looking at erroded compressor, and therefore apu change

  9. at sea level, a 0/low time compressor will make 80 to 85psi at normal ground idle. This increases 

    as throttle is advanced towards take off an TIT increases. The highest I have ever seen was 130psi.

    This was a 0 time engine where the CDP fell in "high" zone of the compressor graph. Compressor

    performance is based on OAT and pressure altitude.

  10. Cool. Ok start is perfect. LSGI looks like like a low time, very strong engine, but

    thats where things get hazy. NGI should be 580 to 600.

     

    After lights out TIT should be 740 to 780. It does look look like the FCU may have

    shifted rich, but you may also have a TD system cutting back too much fuel. Before

    messing with FCU, remove and inspect all thermocouples - replace as required. Make

    sure engine rigging is spot-on. Carry out  yellow box check.

     

    CIT bellows can be adjusted on flight line (if lead seal is still present on FCU) - 1 flat

    decrease (clockwise) is +- 25°C. This will affect the fuel flow across the entire

    schedule, so it may be necessary to reset NULL orifice.

     

     

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